text:
Does integrated inclinometer in glass cockpit makes harder to read its reading?
I am a student pilot with just a little over 10 hours of flying and
when inclinometer (turn-slip indicator) became for me probably the most important flight instrument along with ASI which I constantly monitor during a flight.
We fly Tecnam P92 with 6-pack and inclinometer is a separate instrument.
However I noticed in newer planes with glass cockpit inclinometer is not always on the screen (you have to push button and select specific page), and also to me integrated inclinometer in G1000 for example not very noticeable.
I don't have any experience with glass cockpit, so I want to ask :
Does an integrated inclinometer in glass cockpit makes harder to read its reading?

Well, when you move up into one of those planes, you could consider bringing your own-- see https://hopkinstowingsolutions.com/products/levels/standard-levels/08525.html -- these are only a few inches long and can be stuck on anywhere.  Works exactly like the slip-skid ball (except moves in the opposite direction)-- step away from the bubble, step on the ball.

The integrated inclinometer on glass cockpit raster displays is called the 'brick'.

As a practical matter, since glass cockpit displays were originally developed for transport airplanes with yaw damper systems, where you don't normally even touch the rudder pedals once airborne unless an engine quits, you don't really use it in maneuvering something like a jet manually, unless you are flying it single engine, which is something you are only ever likely to do in the simulator.
It's not as easy to spot at a glance compared to a large physical skid ball, and it's harder to discern small movements, so having it as the sole reference in a light plane where you have to work your feet constantly, and your head is outside most of the time, can be annoying. You will certainly wish the plane had a large skid indicator at the top of the panel, but in the end you'll just learn to get by with what you have, and glance down at it as you would a regular one.
Of course, you have a giant inclinometer, a big bag of meat with appendages sticking out, just sitting there attached to the bottom of your head.  If you are paying attention, you'll notice your own body slouching left or right as the plane slips and skids, the more upright the seating, the better.
Learn to stay relaxed, and sense your own body's leaning tendency when flying, and after a while you'll find you don't even need a skid ball to reference; just use your feet to keep your body straight in the seat.

John, I apologize in advance for my directness here, but I feel I have to "intervene."  Your description intermingles the notion of an inclinometer - a roll meter, with a slip and skid ball - a yaw meter.  Yaw and roll have a friendly relationship in the center of the flight envelope, but become dangerous strangers on the fringes.  A pilot's misguided belief that one provides useful information about the other is immaterial in normal flight.  But in an impending stall, the pilot's inability to intuitively understand yaw separately from roll is a leading cause of fatal accidents.

... (continued) It is quite a simple matter to place an aircraft in an attitude in which your "meat bag meter" (LOL!) will incorrectly interpret yaw as roll, or roll as yaw, and you would be unable to discern which was causing your sensation without a visual cue.

Max, an inclinometer in an aircraft is a yaw meter. It measures the inclination of the apparent gravity felt in an aircraft, which is directly caused by sideslip. The meat bag sensor can only measure sideslip, it needs the Mk I eyeballs to measure roll!

@Max  Well, they are integrated into a single display.  The brick is part of the roll angle display, the little line below the triangular roll pointer.  That IS the skid ball.   You have roll attitude and slip skid presented as one pyramid shaped indication.  On the old Rockwell Collins Proline glass display, the brick was a rectangular box under the triangle pointer, looking more like an actual brick.

@Sanchises Ah, maybe it's my interpretation of the question and answer that went astray.  I've never referred to the ball as an inclinometer for exactly the reason you described,  because the ball reflects "apparent gravity."  I used to work in a field where inclinometer meant something very specific because "actual" gravity was very important.  I just have never heard it referred to an inclinometer in aviation.  Thanks to both of you for your replies.

Completely agree, I guess it derives the name from the working principle. Slip indicator is much less ambiguous - until you consider the yaw string :)

@Max -- In aviation, "inclinometer" is the accepted and widely-used term for the slip-skid ball.  We all know that "inclination" (i.e. bank angle) is not really what it measures, except when the aircraft is parked at rest on solid ground, or whenever the aircraft is being flown along a purely linear flight path (pertains to one-engine-out-operations in multi-engine aircraft.)  If I could go back in time and pre-empt this lingo from ever becoming established, I'd do so happily-- but till a time travel machine is invented, it's what we are stuck with--

I'm not sure what the "brick" is intended to mean in the illustration-- could you consider posting an image showing the "brick" extremely off-center?

The bar at the bottom of the triangle slides from side to side. In older systems it was a rectangle that looked like a brick.


text:
Can you report a crash landing on an emergency frequency even if you are not at the airport?
You see a crash landing near the airport but you're in a car, no other planes have reported the status of the plane, and Approach can no longer contact the plane. Can you report the crash on an emergency or approach frequency to the tower?

just wondering if someone could have reported on emergency just as this one

Which country are you asking about? According to the local laws you might need a ground station license. Just calling the emergency services (911 or whatever your country's number is) is probably simpler.

United States and 911 is probably easier of course

Once a plane has crashed, it is neither airborne, nor traffic, nor controllable. Beyond contacting emergency services for you, ATC is going to be of limited help.

Why do you have an aircraft radio in your car?

If you are in a car, you probably don't have the full picture. Chances are, if the accident happened "near the airport", emergency services are probably already on the way. This is because the pilot would have been communicating with ATC, and would probably have indicated that he was in trouble before the actual accident. Even if the pilot did not have time to notify ATC, if a plane suddenly "dissapears", search and rescus will be initiated.
In any case, if will do no harm to call the normal emergency services (dial 112 or 911 in some countries). Don't overcomplicate things and try to get in touch with ATC - just dial the emergency number directly, and they will know what to do.

What about if you see a crash from your bathtub?

@TomMcW I think that just made my day XD

Yes, you can. If you have an aviation handheld or a ham radio in your car, you can call the tower. FCC rules allow you to use any frequency in an emergency. The catch is that you are supposed to exhaust other means first, so if you have a cell phone you should call 911 first.
Note that this is only FCC rules. Your local jurisdiction might still arrest you for interfering with police or fire operations if you, say, were to report the crash on the local EMS repeater.
It's doubtful, though, so long as you do what you are told and are concise.

I think you might have been trying to ask "Can you report a crash landing on an emergency frequency from your crashed aircraft even if you are not at the airport, and you don't have a mobile phone or have no mobile coverage?"
It's unlikely an ATC radio facility will be reachable on the ground more than a few miles from an airport, so the Answer would be "yes you can", but your message would need to be received by (high-flying) aircraft in the vicinity monitoring the emergency frequency, and I am not sure many aircraft do so anymore. You would be better off trying to contact an aircraft on an your last used ATC or uncontrolled field channel (like 122.9) that might be intercepted by an aircraft in the vicinity.

The question says "you see a crash landing but you're in a car" so I don't think they're asking about radio from your own crashed aircraft. But your point about approach or tower being reachable from the ground definitely applies.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

sort: votes


text:
What aircraft has this pattern of white strobe lights?
Just two nights ago, my brother and I noticed a weird flashing light in the night sky out in the countryside.
We regularly observe by naked eye aircraft flying by,  as well as satellites,  and this was not like anything we'd seen before.
It was only white light (no red, no green) , with the following sequence:
 *            _______          _______

Flash   <-1sec->  strong light  <-1sec->   dim light
The lines above the second and third lights attempt to show the fact that they faded gradually, while the first flash was like a camera flash, sudden and strong.
Every 3 seconds the cycle repeated.
The source of the lights seemed to be the same, i.e the same strobe light. Besides, the aircraft was pretty far away or small: with binoculars, it wasn't possible to discern any other strobe lights or a structure of any kind.
We first noticed the light above Ursa Major, it moved towards Cassiopeia and gradually faded away either because it moved away from us or because of the strong moonlight of that night.

Related: Do lights on aircraft flash in a specific pattern?

Any kind of balloon or drone with a survival strobe attached to it could do this.

Thank you for your answers. No, @mins, it was around midnight, but again, this was periodic and it lasted for about 10 min. No satellite that I've seen produced anything like it. I was curious if maybe military aircrafts have different lights than civilian airplanes and this could be something like that. Or maybe it was indeed what methark suggested, a meteo balloon perhaps? Even though, if that is the case, I would expect to have noticed the light before, some night during all the years that we have been observing the night sky.

Hey. Well. All may apply. It's easier nowadays to spot non-registered scientific experiments with all open technology we have like _italic_RapberryPi (even children can build something that goes high in the sky)italic. But, no one can really answer for sure. :)
About two years ago I saw a movie on YouTube of a 10 years old girl making a hydrogen powered balloon that took a homemade box with cameras, barometer and other stuff) went to the end of the stratosphere (the balloon pop out at the end) - all was recorded just in time.

Twenty cycles per minute means it wasn't an FAA-approved aircraft, so it probably wasn't manned, or even a weather balloon.
Satellites need no anticollision lights.
The bright strobe combined with the longer fading lights suggests something homebuilt.  The light may have been adapted from consumer bicycle lights, which have quite a variety of patterns.  Professional lights such as Whelen's models prefer flickering to fading, for both efficiency and visibility.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
Can I request VFR flight following in a practice area and without a flight plan?
Can you request VFR flight following for your local non towered practice area?  Can you have flight following without filing a flight plan? Can you also receive FF when flying low (800 AGL) locally for separation from pipeline patrols and ag spray planes?

Where in the world are you located?

The term "flight following" implies USA.

Related

(I've assumed you're asking about the US because you used the term "flight following". If you ask about regulations or procedures, please always tell us which country it is and use a country-specific tag if appropriate.)
Can you request VFR flight following for your local non towered practice area?
Yes. I did a tower tour at Huntsville, AL (KHSV) once, and the controllers asked us to request it in the local practice areas. First and most importantly, it helps improve safety and traffic management. But as a secondary point, it counted as an "ATC contact" or whatever they called it, and that helps to justify the existence of the ATC services in that area. That's a good thing for both controllers and pilots.
In general, ATC strongly prefers to be in contact with aircraft in or around their airspace, and I've heard that in multiple presentations from them. If they're really too busy to provide the service then you won't get it, but it never hurts to ask.
Can you have flight following without filing a flight plan?
Yes. They're complementary but not the same thing and they're managed by different groups: Flight Service manages VFR flight plans and ATC manages flight following. In fact, ATC doesn't even have access to VFR flight plans.
Can you also receive FF when flying low (800 AGL) locally for separation from pipeline patrols and ag spray planes?
Maybe. ATC needs to see you on radar to provide flight following and if you're too low you may literally be below the radar.

I do this all the time out of KMSN. They have a "Northeast" and "Northwest" practice area, and a fair amount of flight training out of KMSN and C29.

Same here, my school based at KPWK has us do flight following with Chicago Approach.

For the practice area, a better term would be "Request traffic advisories." Flight following implies receiving radar handoffs to subsequent controllers along your route of flight. The former involves only radar identification locally. The latter requires an entry into the National Airspace System to process the handoffs from facility to facility.

Adding my explicit support to the practice of using different terms for what are different activities and most likely require different keyboard entries on the part of the controller (despite official FAA guidance not differentiating the two terms).

A VFR flight plan is purely used for search and rescue and is completely separate from flight following.


text:
Does a "climb and maintain" instruction override a "climb via the SID" one?
This question pertains to the SNSHN THREE SID out of Ontario, CA (KONT).
Let's say I was originally cleared to "climb via the SNSHN departure except maintain 8,000". Then the clearance is amended after departure to "climb and maintain FL 240".
My question is, am I still required to cross NLAND at or above 14,000, as depicted in the SID?

Very closely related (in fact, it does contain your answer, but wasn't the main point of the question):  https://aviation.stackexchange.com/q/1624/69


text:
Why would the engine quit when turning on the R magneto after an overhaul?
I just finished overhauling a Lycoming O-360; it's currently on a stand, i.e. it's not in the aircraft. I replaced the capacitors and point gaps on both the L and R mags. I adjusted the E-gap and engine timing at 25 degrees as per the engine plate.
I have two toggle switches connecting the P-leads to ground: one for the R mag and one for the L mag. I turned on the L mag only to start and when I started the engine for the first time it fired up right away. But when I then turn on the R mag the engine just stops.
I can start the engine on the L mag only any time. As soon as I turn on the R mag, the engine dies. It’s as if when I turn the R mag on the L one goes off. I did everything I could to troubleshoot but I did not find where the is. What could be the issue?

In many GA aircraft it's common to have a switch "Off - L - R - Both".  Setting the switch to R would indeed shut off the left mag.

Hi Dan, this engine is mounted on a stand and what I have is two toggle switches connecting the P-leads to ground One switch for R mag and one for L mag. When I turn the R mag switch on the L is still on. So, that is as if I were turning the regular GA switch to both...

@DanPichelman By the content of his question I think it's fair to assume he knows how magnetos work.

Wild guess (I do not have wiring schematics at hand nor am I sure such situation is actually possible): What about broken grounding of primary coils, but both still connected together? Then, one magneto switch, while still closed, could provide ground reference, but as soon as you open it too, both coils go floating. Btw. does engine run with R mag only (L shorted)?

Does the engine fire up on the right mag or both mags?

There isn't any way you could have one of the magnetos connected in reverse polarity is there?

Didn't think about that Martin. Will have to create a schematic and see if that is possible. It make sense and it could be...

The engine starts with the left mag toggle switch on as soon as I switch the R mag toggle switch on the engine dies. I guess a better question would be what is causing the R mag circuitry ( when I turn on the toggle switch) nullify the circuit on the L mag?...

"Turn on the toggle switch" might be the issue. You want the circuit open for the mag to run the engine, so technically you're turning the switch off. Perhaps that's being pedantic, but the point I'm making is it's not clear you understand the circuitry based on your description. Further, I think you need to answer Martin's question "does the engine run with L shorted", because it would prove/disprove his theory that the L and R leads may be tied together. IE: If either are shorted, both are shorted.

There's 3 potential problems. Magnetos are very simple in how they operate, and the system basically runs on 3 things that can be easily tested.

Spark plugs, engines can die because of 1 bad spark plug, I've had engines become extremely rough and die within 5-10 seconds when checking R/L because of 1 plug with a piece of lead shorting the electrode.
Magneto itself. I highly suggest against opening up and replacing anything in high-time magnetos in the field for multiple reasons. In case of Slicks, the magneto components are designed to wear at an even rate i.e replacing point contacts or a capacitor is not a wise decision for maintenance or for cost-effectiveness over time. An overhauled 4300 series magneto is ~600 dollars, the labor and parts for internal parts reaches that quickly for a substandard magneto as the finished product. I can't speak as much on Bendix but magnetos are a mix of old, complicated, and mechanical that means high wear and high chance for improper reassembly. In this case I assume your O-360 is running 437X Slicks.
Wiring in the ignition switch. You cannot improperly wire a magneto(as far as the operation of the magneto is concerned on a 360, any absence of wires won't stop the operation), and personally this is the least likely of the 3 especially if you didn't touch the ignition. Improper wiring of the backend or improper switch installation could cause this, but again I would highly advise checking the 2 before.

I know this is long past a point of help but I think it helps to explain for anyone else interested

If the R magneto was inadvertently providing a very advanced spark the premature ignition would effectively brake the engine very quickly. I'm not familiar with your engine but did have that happen with a classic Kettering (points/capacitor/distributor) ignition in 1977.


text:
Is there any way to reduce the noise and vibration in a C-130 Hercules?
We are using C-130 B and E Models with T-56 A-15 engines and Hamilton Sundstrand 54H60-91/117 propellers. A lot of vibration and resonance are felt on these military version aircraft even after using solid state synchrophasing and conducting prop balancing.
I wanted to know if there is some system to make the aircraft quieter. Except for shutting down the engines of course :)
Are there any resonance controlling items to make the passengers more at ease?

Or noise cancelling headsets for everyone?

Line the cabin walls with Sound Proof material, such as  http://www.aircraftspruce.com/menus/ap/soundproof.html  or other similar material approved military use.  Of course, the walls may already be lined with something.

I really like the "shut down the engine" solution

I worked the C-130E/H my whole stint in the Air Force. To this day, I have never slept as soundly and as comfortably on an airplane as I did on those birds. When the props are synced, the hum and vibration was so relaxing. I used to string a hammock up from one side to the other and just rock away like a baby. I honestly don’t think there is anything to make it quieter as the military never really cared much about how much noise we were exposed to.

Active vibration control systems exist for some aircraft, though I doubt an ex-military type would have anything off the shelf. There is a system from Lord (the engine mount people) that is intended to counter the vibration from a helicopter main rotor to improve passenger comfort, among other things. This is their claimed reduction:

AVCS Product Brochure
They focus on helicopters but sell components as well, and may be able to customize something that could work for you.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
How is a composite fuselage repaired when structurally damaged?
In case of FOD, a fuselage puncture for example, what is the repair process? Considering time, complexity and cost, how is compared if it was an aluminium fuselage?

This is very broad @Anton, are you thinking about a specific type of damage?

Speaking for myself and not in aviation, I find fiber-reinforced plastic much easier to repair than anything made of metal. It's basically doing fiberglass layup, but with a different fiber and maybe different resin.

@Harper, I agree with you when it comes to FRP repairs done to simple everyday objects. I have done some repairs to Fiber-reinforced-polyester surfboard, and found it quite simple as well, but in aviation may be a whole different story. And I´m also interested in the comparison with aluminium repairs.

This is pretty broad and covers a wide range of techniques.  But the airplane Structural Repair Manual (SRM) provides guidance, depending on the extent of the damage.  Typically it involves excising the damaged or delaminated structure and patching the affected area.  As with metal airframes, if the damage it too extensive the airframe may have to be written off as a total loss.


text:
Is "General Aviation" a well-defined term in the US, in the EU and/or elsewhere?
In this earlier question I tentatively assume that GA means civil aircraft operations other than scheduled passenger transport - what I think of as "airliner" operation though it could include quite small aircraft operating a scheduled fare-paying passenger service.
It has been suggested to me that GA can sometimes or often be used to mean all aviation in general - perhaps in some contexts more than others.
I had thought that most people here used GA to mean aircraft operations other than scheduled service, but now I have my doubts.
So, is there an authoritative definition of GA in the USA (and elsewhere, or worldwide) or is it a vague and varyingly interpreted general phrase that I should avoid to prevent misunderstanding?

As you have shown, the term is used in different ways in different contexts.

It's definitely not "all but scheduled passenger service" -- I don't think anyone would class FedEx as general aviation.

@Tyler: Good point, Instead of writing a somewhat self-answering question I'll split my Q into a Q and an A and see what happens.

It is GAT (General air traffic) which actually means  all aviation in general  (except military and some test flights).

In common parlance, "General Aviation" typically means "not-airline".
In the Pilot/Controller Glossary, the FAA now defines General Aviation as:

That portion of civil
  aviation that does not include scheduled or
  unscheduled air carriers or commercial space
  operations.

and it gives the ICAO definition:

All civil aviation
  operations other than scheduled air services and
  nonscheduled air transport operations for remuneration
  or hire.

Both these definitions are closely tied to commercial operations, and they go out of their way to point out that non-scheduled air carriers are NOT general aviation. Note that "civil aviation" would mean "not military".
Historically the term has been very colloquial, and to some extent you will still find different definitions from everyone. However, IMHO these are the most clear definitions available.

Well, technically "not airline, and not military", but yeah.  :-)

The FAA does not include a definition of General Aviation in CFR 14 (aka Federal Aviation Regulations) Part 1 (General Definitions and Abbreviations), but, from a functional perspective, in the US, GA is generally used to refer to any civilian operations falling outside of Part 121 and some Part 135 operations (Commuter and Charter Operations - regional feeders have and may still operate under this section if they can meet the requirements, as it is more relaxed and easy to comply with than part 121).
With respect to the FARs, it's important to remember that Part 91 covers ALL types of flight operations UNLESS its provisions are EXPLICITLY overriden by another paragraph (as would be the case with an air carrier's Operating Specifications, part 121, 135, and other sections dealing with more specialized aerial applications). Part 119 also deals, in a very general sense with conducting flight operations for compensation.
IMO, you're not likely to go wrong using the term to refer to everything civilian outside of scheduled carrier and medium/large cargo operations (e.g. Atlas, Evergreen, FedEx, UPS). The caveat is, of course, that GA operations are so diverse that this is more of an "everything else" category rather than the much clearer images conjured up by a flag/commutter/regional carrier or a large cargo operator. If you're unclear about whether a specific application or air operator falls under GA, go ahead and ask.
The FAA division of airports is more likely meant to reflect that certain airports have certain primary intended purposes (e.g. many of the nation's largest airports do not allow Part 91 operations, only air carriers) and may require certain types of infrastructure in order to allow them to perform those roles.
And yes, using a 737 as a personal plane under Part 91 would fall under GA - Boeing even makes a specialized version just for that, see the BBJ.

Thanks +1, sorry for editing my Q out from under you while you were answering. I guess readers will work out that your 737 reference applies to a part of my Q that I moved into an answer :-)

@RedGrittyBrick - no worries; also, with respect to your airport question, see FAR 139.5 for the FAA's actual definition of different airport types.

Don't forget that that 737 would likely be a Part 125 (large aircraft) operation, not Part 91 -- there's also fractional ops under part 91K and ag spraying under part 137

@UnrecognizedFallingObject - with respect to aircraft operation, Part 125 supplements Part 91 - Subpart J deals with and clarifies a number of items that would not typically be an issue in smaller aircraft, but your point is well taken in that operating a 73- under Part 91 would also have to comply with additional requirements in other paragraphs (or subpart K, if a fractional op).

The term "General Aviation" is used differently by different organisations.
It may be best to either avoid it or only use it where it's meaning will be clear to international or non-expert readers.

From what I've read,
Use vs Type
These sorts of classification apply to the use (i.e. "operation") rather than to the aircraft type (make and model) - you could use a 737 as a personal airplane and your use would not be governed by regulations that apply to 737s operated by typical airlines for scheduled passenger transport.
FAR lore
I've read people say that, in the USA, GA means anything under FAR 91 and FAR 135 but scheduled airliners come under FAR 121 (I may have the numbers wrong, please correct)
AOPA say "General aviation (GA) is all civilian flying except scheduled passenger airlines."
ICAO define general aviation as all civil operations other than scheduled air services (plus a bit of hand-waving)
Transport Canada say "General aviation (GA) is all civil aviation operations other than scheduled air services and non-scheduled air transport operations for remuneration or hire".
FAA divide airport operation into Commercial Service, Cargo Service, Reliever and everything else "commonly described as General Aviation Airports". But I couldn't find an FAA definition that applied specifically to the aircraft (or to aircraft operations other than at an airport).
EASA seem to define operations primarily into Commercial Air Transport (CAT) and Non-Commercial (NC) and use the phrase "general aviation" in a more general all-encompassing sense.

authors: Vladimir F Героям слава


text:
What is this closed cabin / open cockpit biplane from the 1910s?
This photo was taken when Lieutenant Marix RNAS visited his old school, Radley College in Oxfordshire on 30 May 1914. Marix was awarded in October 1914 the DSO for bombing the Zeppelin sheds in Dusseldorf which was the first successful bombing raid of the war.
Is there anyway of identifying the aircraft? Perhaps from the registration number 104 shown on the aircraft tail fin?

Welcome to aviation.SE! Do you have any more information that you can share? It would be great to know the location/country, for example.

The photo was taken when Lieutenant Marix RNAS visited his old school, Radley College in Oxfordshire on 30 May 1914. Marix was awarded in October 1914 the DSO for  bombing the Zeppelin sheds in Dusseldorf which was the first successful bombing raid of the war

That's great information, I edited it directly into your question; please feel free to re-edit if you prefer.

I submit the Sopwith Type D "3-Seater".
No.104 appears to be one of the first Sopwith aircraft produced for the Royal Navel Air Service (RNAS). The RNAS received at least three examples (No.33, No.103, No.104) one of them being the original prototype, known as the Hybrid that was later rebuilt and delivered to the RNAS. The Hybrid was made from combining the fuselage and tail of a Coventry Ordnance Works biplane and the wings of a Wright Biplane, the Type D retained the wing warping method of lateral control used in the Wright biplane until fitted ailerons after entry into service.  Wikipedia
Comments about No.104 found in the Kingstone Aviation page for 1914: (All bold formatting added by me)

The Daily Telegraph leader sums it all up. “These aircraft represent an extension of our sea power; they are the scouts of the future.  A fleet of battleships unattended by aerial craft will be blind.  Cruisers even if able to steam at 30 knots will be inadequate.  Their range of vision is limited; their rate of steaming is insufficient.  The seaplane on the other hand is the fastest and handiest ship ever contrived by the ingenuity of man – with a speed of 70 miles an hour and a capacity for manoeuvring which defies competition.  In two years the rate of flight has doubled and no one can say that the limit has been reached.  A fleet without aerial squadrons will be robbed of the essential intelligence which is the talisman of victory – the foundation of successful naval tactics.  As we are forced to develop our sea fleet, no effort must be spared to build up the complementary air service.”
It is no surprise then that the RNAS are upgrading their older wing-warping landplanes by placing orders with Sopwith for sets of ailerons for “Type D” biplanes No.33 and No.104 at a cost of £198.10.0d a set.
On 25th July 1914 Sopwith get an order from the Admiralty to repair “Type D” No.103 and retro-fit with the ailerons recently ordered for No.104.
On 2nd August 1914, reflecting the deteriorating situation in Europe,
  the Order of Battle is issued by the Royal Naval Air Service.  The
  RNAS now owns 95 aircraft:- “57 seaplanes, 34 aeroplanes and 4
  monoplanes”.  Only 46 of these are considered operational and assigned
  to the nine Naval Air Stations. Only 3 of the 15 aircraft supplied to
  the Admiralty by Sopwith over the last 19 months appear amongst those
  46 - “Type D” No.104 at Eastchurch, “Anzani Pusher Floatplane” No.123
  at Grain Island and their original Bat Boat No.38 at Felixstowe.

Comments about No.104 found in the Kingstone Aviation page for 1915:

On 11th January the Sopwith “Type D” No.104 which has been at Eastchurch since early September suffers a failure of its 80hp Gnome engine.  Flt. Lt. I.G.V.Fowler manages a forced landing on mud flats by the River Blackwater but this ends the 17 month career of one of the earliest Sopwith machines still in naval service.
There is news that on 20th January long-serving Sopwith “D1 Three-Seater” No.103 crashed on landing at Eastbourne but is probably repairable, unlike sister-ship No.104 nine days before.

Images found here: kingstonaviation.org

Look at how small the tail fin & rudder are. Not much surface area there.

I suppose that could do it. All moving fin must not have been help stability wise. The rudder on my Cardinal has a lot less area than the fin.

Other versions of the 3-Seater had a larger tail.  I suspect that they found that the smaller tail was not sufficient.

Thanks very much for identifying the aircraft, I have now been told the photo was taken in May 1914- its fits with the Sopwith diary for 1913 on  kingstonaviation.org


text:
What does "lower flatness" mean in airfoil terminology?
What does lower flatness mean in these parameters of a Glenn Martin airfoil?

Just a guess - something to do with the amount of deviation from a planar bottom of the airfoil.


text:
Is the lift produced by a wing with a 10° flap equal to the lift created by a wing with 10° AOA but with no flap?
After reading this article I would like to know if the lift produced by a wing with a 10° flap is equal to the lift created by a wing with 10° AOA but with no flap?

No, there is a big difference between an entire wing being at an angle of attack and a small part of the wing being at an angle of attack.

On top of that, a good insight can be gained by referring to thin airfoil theory

... and what is that "big difference"?

No.  While the article correctly mentions that extending flaps kind of has the same affect as increasing your AoA, the lift would not be the same.
First of all the flaps are only installed toward the root of the wing and not along the entire surface.  So flaps only increase lift on a certain portion of the wing.  Increasing the AoA increases lift on the entire wing so increasing your AoA would increase your lift more.
The main advantage of flaps is that it reduces your stall speed. An aerodynamic stall happens when there is a flow separation along the upper surface of the wing.   This flow separation happens at the critical angle of attack so increasing your AoA too much is dangerous.  Employing the flaps allows you to increase lift without increasing your AoA thus preventing the temptation of a pilot to stall his airplane during landing.


text:
Do stall strips mean that wing washout is not required?

The Wikipedia page on stall strips states that AA-1 Yankee airplanes used stall strips to avoid tip stalls (and spins) because wing washout couldn't be used.
So my question is: can two stall strips placed on each tapered wing (tapered wings love tip stalling) eliminate the need for a washout?
Secondly, what does it mean for a wing to have a washout of 6°? Does it mean the angle of incidence at the root is 6x greater than the tip?

Your second question might already be answered here

Rectangular wings can get away without washout because that planform tends to have favourable root to tip stall progression as a characteristic of the rectangular shape.
The stall strips aren't really to change the root to tip stall behaviour as a substitute for washout; their job is to generate a local flow separation, just prior to the natural stall, who's turbulent flow can be felt through the airframe and at the elevator while the rest of the wing is still unstalled.  That's why they are just short sections in front of the outer parts of the horizontal tail, so that the burble they produce will be felt through the controls well before the rest of the wing lets go.
The Yankee had a NACA 64-416 laminar airfoil which had an abrupt stall and very little natural pre-stall buffet - helped by the strips.  Later variants got a revised airfoil with a drooped nose to make the stall itself more gentle, but they still retained the strips to provide the pre-stall buffet.
Many years ago I flew a Yankee that was in a flying club I was in, and it was considered a demanding airplane.  The stall strips made it a bit less dangerous than without, but it still took careful speed control when landing.  If you got too slow it would start to sink and pulling a bit more pitch had no effect.  It had a reputation as a very "hot" airplane for something with only 108 HP.
On a tapered wing, you would be adding stall strips for the same reason as the Yankee's wing, near the root forward of the outer end of the horizontal tail, to provide a distinct pre-stall warning buffet.  If your tapered wing had no washout but had the strips, all that would happen is you would get a pre-stall buffet that wouldn't be there without them, but then when you get to the wing's stalling AOA the whole thing goes at once because it's still a tapered wing with no washout.
Some designers get some of the benefit of washout without twisting the wing by varying the airfoil section itself from root to tip.

Many thanks!....One question: if vortex generators are put on the outer wing(e.g 1/3 of a wing),  to keep airflow attached as the root of a tapered wing stalls, does this cancel out the need for washout?    The reason am asking is 'cos, am trying to design an ultralight wing:which is tapered and I want to avoid washout for the sake of building simplicity.

Yes VGs are used for that reason.  Leading edge VGs raise the stalling AOA by several degrees, maybe a 3rd of what you get with a leading edge slat.  I call them "poor man's slats".  The VGs have to be placed at a sweet spot that is just forward of the separation point at stalling AOA.  You'll have to determine the location and spacing by experimentation.

6 degrees of washout means the angle of incidence is 6 degrees lower at the tip than the wing root, causing the wing root to stall first.  Leading edge slats serve the same function, especially in combination with trailing edge flaps near the roots.
Whether these strips would replace washout is debatable, trying to "save" an approach by pulling
hard on the elevator is not.  The end (literally)
result is the inside wing, slower than the outside
in the turn, stalls first, the plane then rolls and falls to the ground. Only immediate opposite rudder, along with relaxing the elevator, will help if you catch it in time.

Secondly, what does it mean for a wing to have a washout of 6°? Does it mean the angle of incidence at the root is 6x greater than the tip?

This means that at wing root the angle of incidence is 6° greater than the at wing tip.
For example, if the incidence at tip is 2°, with washout of 6°, then the incidence at root is 8°, so the wing stalls and has stall disturbances much earlier at root. This helps to better preserve aileron authority.


text:
What was the lowest ground speed landing?
Planes fly if their speed relative to the air is high enough to produce lift. If there is no wind, the plane's air speed will be the same as its ground speed. If flying against wind, its ground speed will decrease.
That said, what was the lowest ground speed during landing ever recorded?
I think there should be some rules against landing with the wind from behind, as it would make the plane go too fast, but what about opposite? Has any plane landed with zero, or close to zero ground speed? How about 'negative' speed, pushing the plane backwards relative to the ground?
I found some information about the highest ground speed while in flight, but I'm interested in the exact opposite.
Highest points for answers with passenger airplanes (737 etc), helicopters are considered cheating.

"highest points"?

How about 0? Harrier's, F-35s, etc... https://en.wikipedia.org/wiki/List_of_VTOL_aircraft

Pretty sure someone asked about negative ground speed a while ago, so lowest becomes most negative. See for instance https://aviation.stackexchange.com/a/65233/4269

There is not an absolute "rule" about landing with a tailwind.  There are some airports that are very much one-way (due to e.g. being sloped, or having mountains at one end),  and some commercial airports restrict landing directions for e.g. noise abatement, so landing with a modest tailwind is normal.

Considering groundspeed as a vector, 0.
You can land vertically with strong headwind: Could a plane land vertically in a strong headwind?
As the answers to the question, previously linked in Flexo's comment -  Is it possible to fly backward if you have really strong headwind? - detail, the answer is "yes". It's even possible to have one's groundspeed vector directed tailwise.
The Antonov An-2, can be flown at as little as 25 knots of airspeed, and safely landed below that speed. When turned into decent headwind, it can be kept in hover relative to the ground. I haven't found a video of a hover landing, but it's been reported to be done. With a 12-passenger capacity, it's no 737, but it can count as a passenger airplane, and it's designed to do this.
Vertical landings of smaller planes have been filmed:

 (thanks bukwyrm).
P.S. Vector representation is most appropriate for groundspeed, as it's not normally directed along the aircraft's longitudinal axis due to side winds. So landing "backwards" can be considered positive groundspeed once again.

Formally thinking, the negative ground speed is possible then (touching ground when flying backwards) but the aircraft may not like landing tail forward.

Hover landing: https://www.youtube.com/watch?v=WPyCywd4o5E

Has a plane ever actually landed backwards other than in an accident (deliberately or accidentally)?

The famed German Storch (Stork) of WWII vintage was specifically designed to have a tiny landing and take-off run. It was often used for missions where today we'd use a helicopter. It's alleged it could hover in a decent breeze, this video shows what could be described as a landing run measuring about 2 metres:

Both landings shown in the video had a ground roll much longer than 2 meters. (But still amazingly short by normal standards!)

Zero.  In addition to the examples given in other answers, this answer to a related question shows a video of a hang glider executing a zero-groundspeed landing: Is it possible to fly backward if you have really strong headwind?


text:
What does this 'R' number mean on the ND of this Airbus?
This number here, what does it mean?

That is the cross track error shown on the Navigation Display (ND):

9 Cross Track Error
This is the aircraft's lateral deviation from the active leg of the flight plan (related to the great circle route). It is indicated in nautical miles (NM), with the letter R (right) or L (left), according to the position of the aircraft with respect to the flight plan.

(Airbus A320 FCOM - Indicating/Recording Systems - Indications on ND - Rose NAV mode / ARC mode)
In your example, it indicates that the aircraft is 19.1 NM to the right of the flight plan (shown as the dashed green line). The reason seems to be the presence of moderate and heavy precipitation along the planned route (shown as the yellow and red patches from the weather radar). The flight crew switched to heading or track mode (the solid green line indicates the current track) to manually fly around the weather.

19.1NM Right of flight plan track

And in case anyone wonders why, pretty obvious it is due to the weather that can be seen on the weather radar :)


text:
Does the A320 have an audible A/THR disconnect sound?
Say for example, the Autothrottle was engaged (while Autopilot not engaged), but for some reason was disconnected, is there an audible cue for this event? What sound does it make?

Listen.

Yes, there are both visual and audible cautions triggered when the A/THR is disconnected. The details depend on whether it was a standard disconnect (via the instinctive disconnect buttons on the thrust levers or by setting the thrust levers to idle) or a non-standard way:

Standard diconnection triggers temporary ECAM message and caution light. Single
chime sounds.
Non standard disconnection triggers caution light and ECAM message removed only by
a pilot action. Single chime sounds.

(Airbus A320 FCOM - Autoflight - Flight Guidance - A/THR Disconnect Caution)


text:
What Makes G1000 NXi Different From G1000?
The new displays are installed on the brand new Cessna aircraft and upgrade plans are ready.
But what is the difference from the G1000 that was there from the early 2000s? Is the tablet/phone compatibility (Which can be used for charts) what makes it different? I cant find comparisons on the internet.
In short. What makes G1000 NXi better than G1000?

The official Garmin announcement lists all new features.
The new hardware features are:

faster processors resulting in faster start-up, map rendering, etc.
more modern animations
a new design with better readability
LED back-lighting (increased display brightness, clarity and better dimming)
lower power consumption

The new software features are:

wireless connectivity (database updates, flight plan transfer and information shared with a mobile device running the Garmin Pilot or ForeFlight apps)
flight path for visual approaches (both for visualization and auto-pilot)
full map overlay on the HSI on the PFD
SurfaceWatch (similar to a RAAS)
full ADS-B compatibility

Further features listed are:

Advanced Doppler weather radar capabilities, including ground clutter suppression and turbulence detection as options.
COMM frequency identification displays the station ID, as well as frequency type.
Display of sectional charts, as well as IFR low/high enroute charts on the MFD.
NEXRAD weather radar imagery can be overlaid on the moving map and animated on the MFD, as well as the HSI map.
Vertical Situation Display (VSD) incorporates terrain profile view on the MFD, taking into consideration the active flight plan, altitude constraints and winds aloft.
Pilots can preview departure and arrival procedures on the MFD prior to loading and activating the procedures.
Pilots can optionally overlay European Visual Reporting Points (VRPs) on the moving map, as VRPs are standard within the navigation database.
Three-color terrain shading incorporates green, yellow and red contouring, which depicts the aircraft is 2,000, 1,000 and 100 feet above ground level (AGL) respectively.
Aircraft maintenance personnel experience faster system software upgrades and streamlined equipment replacement.


text:
Do fighters or bombers ever ditch their weapons?
I was just reading about the reasons why commercial aircraft will sometimes need to dump (or otherwise consume) their extra fuel. Things like decreasing landing weight, speed, reducing fire risk, etc.
It seems like the same would apply to fighter and bomber aircraft with their weapons as well.
Do these aircraft ever ditch their weapons (presumably in a disarmed state) if forced to land in an emergency? If not, why?

Probably depends on the emergency and what the weapon is.

Yes they do. Even nuclear bombs

 Introduction
I have experience flying the A7-E Corsair off the USS Nimitz in the mid-1980's. There were typical scenarios that would require us to either jettison fuel, ordinance, or other stores. Below you will find a description of some of these scenarios.
 Take off
I was in a brief with my Skipper for a night hop, and he asked me perhaps the best question any one ever asked me in a brief. I didn't have an answer, but started practicing that flight until I left the Navy. He asked, "Salt, what do you do after your take-off checklist while under tension, and right before you salute for the catapult shot?" He went on to describe what he thinks and does.

Reach out look at and touch the salvo jettison button. Physically touch it.
Grab the lower ejection handle.
Salute and come back inside to look at the airspeed indicator. If you don't have 175 knots by the end of the cat stroke eject. No questions.

Every catapult shot I took from that day on I practiced his advice. There were 2 buttons available to jettison stores attached to the pylons under the wing. One was the select jettison, which allowed you to pick a location under the wing, and then jettison that store. The salvo jettison was a big red button close to the middle of the instrument panel, and did not discriminate. Both buttons were next to one another. All stores were ejected from the pylons. If you had a catapult shot that didn't give you enough airspeed off the bow this was an option to buy some immediate lift.
I came off Cat 2 one day and made my clearing turn. As I was cleaning up the aircraft and heading to the squadron's rendezvous point I saw something in the ocean. You know what it looks like when you take a big stone and throw it in a pond? It disappears but leaves a foot print of turbulence and bubbles on the surface of the water. Well, I looked down over the water as I was heading out and saw that kind of footprint. It was as big as an aircraft and persistent, just kind of staying there without dissipating. It looked like an aircraft had ditched, but an A6 had gone off just prior to me and used the salvo jettison getting rid of all his stores.
 Tanker Duty
At times the buddy store would malfunction, and stop transferring with 500 pounds of fuel sloshing around in one of the tanks on the aircraft. You couldn't take a trap with a partially full fuel tank. The slug of fuel would shoot forward, and the tank might be ripped off the pylon. Fuel tanks were not too expensive, but the buddy store had all sorts of hardware and electronics it. Squadrons didn't like to lose these. I had a buddy store on pylon 3 and a drop tank on pylon 4.
On my last rendezvous the buddy store failed to finish transferring all the fuel in my drop tank on pylon 4 and so I said goodbye to the aircraft on my wing and called maintenance to discuss the problem. The maintenance officer got on the radio and we went over the NATOPS procedures for jettisoning the fuel tank. We found a stretch of ocean that was clear of any traffic, and after going over it once he emphasized to me, "Look at the station you selected and read it off to me." After telling him it was number 4, he finished with, "Now make sure you use select jettison and not the salvo button." I pushed the select jettison button and looked in my mirror to see the fuel tank drop away from the wing, and quickly looking in my left mirror caught the buddy store falling away as well. I swear I pushed the select jettison button, and had that image in my head. I had of course hit the salvo jettison button out routine practice of reaching for the salvo jet button every cat shot.
 Air Combat
The performance characteristics of the A7-E put it at a disadvantage against fighters designed specifically for air-to-air combat. The training we received for dealing foreign fighters suggested that, once engaged ingressing to the target, we would make a defensive turn, and if the enemy got behind our wing, jettison our bombs and other stores, e.g. fuel tanks fully committing to the fight. The fuel consumption while at military power at sea level for the subsonic A7-E was around 6,000 pounds per hour, which is quite good. On the other hand, a fighter in burner, by the time it gets to behind the A7's wing line will be fuel starved. To stay in the fight with burner will require a kill within 30 seconds.
 Landing & Dumping Fuel
We brought back weapons all the time to the ship. A good example is the AGM-62 Walleye, a 1,000 pound bomb with a television camera on the nose and in-flight avionics for "guiding" its flight. This was done either by the delivery aircraft, or a second aircraft in a stand-off position. We seldom dropped this weapon in practice, and would bring it back to the ship. We would launch with AIM-9's, when the fighters weren't hogging them all, and bring those back too.
The following acknowledges that there are Rules of Engagement, and within these rules and I will say this. As an attack pilot my mission was to put bombs on target, and if I didn't get the bombs there someone had to go back the next day and finish my job. The enemy would be waiting for that next strike. If for some reason I couldn't get to my target I would find a target of opportunity. Attack pilots don't bring their bombs home with them. Drop them somewhere.
As for fuel, tactical high performance aircraft from the time they take off are emergency fuel in a sense. By the time you got to the landing sequence you were almost always short on fuel. Emergency fuel is at 1,200 pounds and calling the ball at 2,500 pounds was pretty typical. That gave you 30 minutes in the pattern. A divert to another field where there was a climb en-route would eat at that reserve a bit more aggressively.
Every once in a while you might come back heavy with fuel. The maximum field landing weight was 5,000 pounds, and above this weight the procedure was to dump fuel. There were altitude restrictions on how low you could be to do this. The 5,000 pound limit was because the brakes would overheat. This would eventually cause the fusible plugs to blow releasing the pressure in the tires sometime later. This was to be avoided.
 Taking the Captain to NAS North Island
While at NAS China Lake I was working with the A7E software development team on aircraft software enhancements. I would go out and test the software in the operational environment. The detachment there had an A7E Trainer, which was a two seat version of the single seater. I would at times ferry personnel where required. I got a call to take a Captain to NAS North Island and this was a quick hop. I ended up landing over weight. After dropping off my cargo I headed out to the hold short and got a call from tower informing me that my breaks were smoking. I decided to get airborne so I could get home, and if the tires blew in flight, take the gear at my home base. Left the wheels in the air stream climbing out staying below the 220 knot restriction for lowering the gear. The flight was incident free.

Great, real world, examples. Thank you for sharing your experiences. The one about dropping the buddy store made me cringe!

So did the Maintenance Officer. I have to smile today. I came home and stated what I believed. I pushed the select jet. The Maintenance Chief came to me after they had checked out the electronics and said they found nothing wrong. I swear I still see my finger hitting the select jettison.

Worth noting that during WW2 bombers would usually ditch all remaining bombs before landing as the risk of one breaking loose and going off by accident was too great. This story mentions the following:

Having reached Belgium, the formation was forced to turn back because
  of the weather. They received a message to jettison their bombs over
  the Channel, as the risk of accident (and explosion) upon landing was
  high.

Yes, military bombers do routinely dump weapons to decrease weight to reduce the hazard during an emergency landing. Sometimes dumb bombs are dumped just to save weight or as standard procure to reduce risk at landing.
In this NOAA map of the Gulf of Mexico you can see several "Explosives Dumping Areas."


text:
What is the term for an aileron that’s also used as a ground spoiler?
Ailerons and spoilers1 have a considerable amount in common; both are wing-mounted panels, hinged at their leading edges, that move up and/or down to alter the aircraft’s aerodynamic characteristics.

Ailerons are mounted on the wing’s trailing edge, are useful only during flight, and move up on one side and down on the other to increase the lift of one wing, decrease it on the other, and roll the aircraft to one side.
Spoilerons (also known as “roll spoilers”) are mounted on the wing’s upper surface, are useful only during flight, and move up on one side to decrease the lift and increase the drag of that wing, rolling and yawing the aircraft towards that side.  They are more useful than ailerons at low speed, as (unlike ailerons) they do not increase the angle of attack of any part of either wing, create proverse rather than adverse yaw, and, thus, are immune to the crossover-airspeed phenomenon inherent to ailerons.2
Lift/drag spoilers move up symmetrically to decrease the lift and increase the drag of both wings simultaneously, either in flight (when they are called “flight spoilers”; this enables the aircraft to descend more quickly, or to use a higher power setting on approach,3 without excessively increasing its speed) or on the ground (in which case they are known as “ground spoilers”; this enables the aircraft to slow down more quickly during a landing or rejected takeoff, both by increasing the aircraft’s drag and by dropping its weight onto the wheelbrake-equipped main landing gear); they can be (and almost always are) combined with spoilerons, to provide a single spoiler system with both spoileron and flight/ground spoiler functions.

As ailerons are useful only during flight (since an aircraft generally can’t  roll left or right on the ground,4 due to said ground being in the way), the aileron panels on most aircraft don’t do much of anything useful on the ground.  It isn’t too hard to visualise a system in which the ailerons, when on the ground, deflect upwards to decrease lift and increase drag, acting as additional ground spoilers, but I’ve no idea what these combined ailerons/ground spoilers would be called; “spoileron”, as noted above, is already taken by a different type of system (one using asymmetrical spoiler deflection in flight to roll and yaw the aircraft).
What would be the term used for a control surface that functions as an aileron in flight, and as a ground spoiler on the ground?

1: (and flaps)
2: Additional advantages of spoilerons over ailerons are that, being located on the wing’s upper surface rather than at the trailing edge, they do not interfere with flap placement, and are much less prone to causing the wings to twist when deflected; as a result, some aircraft use only spoilerons (and no ailerons), either to allow flaps to be placed along the full span of the wings (thus reducing takeoff and landing distances and speeds) or to allow the use of thin, flexible wings at high speeds without encountering wing-twist-induced control reversal.  Disadvantages of spoilerons are their lower maximum control authority at intermediate speeds and their greater total drag penalty.
3: A higher approach power setting makes go-arounds safer by reducing the time needed for the engines to spool up to full power; this is especially important for jets, as jet engines are slow to accelerate, and accelerate ever more slowly from lower and lower initial power settings.
4: Barring a collapse of one or more of the main landing gear, which is not generally a planned, or desired, occurrence.

Do you know of an aircraft that uses ailerons as spoilers?

The problem with your suggestion is that when deflected upwards together, the ailerons would run out of wiggle room as differential ailerons. This can be designed for, as in the elevons on tailless aircraft, but it makes for bigger and heavier control surfaces. Moreover, ailerons on a swept wing are already far enough back to act as elevators, and would excessively upset pitch trim. The only descriptive term I can think of is "impractical".

@GuyInchbald: Hence the part about only using them as ground spoilers, when they are no longer needed (or useful) as ailerons.

@Bianfable: I do now, thanx to ymb1's comment below yours.

The ailerons are quite useful controlling the airplane during takeoff and landing as well as in gusty conditions.  Proper takeoff and landing technique requires the ailerons to travel almost full travel to counteract the effects of the wind.  I doubt if changing the ailerons to make them ground spoilers would increase safety.  I would say it would decrease safety considerably.  Once the airplane is to a speed slow enough that it is not useful for takeoff and landing, you will still deflect the ailerons to counteract the wind for taxi.

@Sean Oh, I see what you mean. I am accustomed to calling devices used only after landing "lift dumpers".

General comments embedded within question about not needing to use ailerons on ground could be revised-- certainly does not apply to Cessna 152 or Piper Cub  in strong crosswinds but might possibly apply to a heavy airliner with fairly widely spaced main landing gear.

The action of a ground spoiler is essentially that of a lift dumper, which also acts as an airbrake.
As far as I am aware there is no special term for an aileron which also performs this function. Several Airbus types use the technique but their literature just calls them ailerons. On the A380 at least the spoiler action is initiated by the Speed Brake lever.
Of course, "spoilerons" are not quite the same, as these are spoilers used differentially for roll control during flight.
It is not too uncommon for a device named for one function to do double duty in another. For example "landing flaps" are often also (partially) deployed for takeoff - as of course is "landing gear" - and on some older types the servo tabs also double as trim tabs.


text:
How to modify an amateur kit build with wing hard points
I plan on modifying an amateur-built all-metal kit plane so it has a hard point under each wing where various external loads (cameras, probes, etc) can be fitted to (university research). The location would be approximately mid-wing. The aircraft in question is a Sling 2. It will be registered in Germany as an experimental with a permit-to-fly.
I was unable find any resources on how to tackle this engineering problem on small aircraft. The resources I have access to are all for large aircraft and are somewhat "oversized" in my opinion.
We are talking external loads up to about 5 kg (11 lbs) in mass.
An aerodynamic envelope expansion will be needed for each external load but how do I design the wing for it?
Edit: I found a builders log of a 75% Tucano-R Replica who did this, however there is no explanation on the engineering part. It looks relatively straightforward with just two thicker plates attached to a rib.

In what jurisdiction do you intend to operate?

@AEhere good point, aircraft will be registered in Germany.

"Alterations on critical components must be EASA-approved via STC, in accordance with TIP paragraph 2.2 (Design Approval Procedures for Supplemental Type Certificates (STCs))." I don't think you will be able to pass any modifications to the wing as non-critical.

@AEhere this is only true if not registered as an experimental. When registered as experimental there is no type certificate so there can't be a STC?

correct, I am adding something about experimentals to my answer now, but it's kinda hard to find info on permit-to-fly applications.

@AEhere thank you for your input - that's exactly the reason why I turned to this place here … I was unable to find much on it.

you're welcome, I wish I could help more as I worked on this same problem for an aircraft in the same category, but was not too involved with the permit-to-fly shenanigans. Of course I now regret not having asked more questions of the people that were.

In terms of the actual engineering, have you tried asking the original designer for help?

@RobinBennett I did, their answer was basically "we are very busy - when you came up with something show it to us and we'll have a look at it". This is basically the point I'm at. Not wanting to waste their time and get an acceptable solution (with your help).

You will most likely need a Supplemental Type Certificate from EASA
According to their FAQ, emphasis mine:

My aircraft has been modified in the USA by Form 337 action. Can EASA accept this?
Answer
EASA accepts alterations on non-critical components that are substantiated via Form 337, as detailed in the EASA-FAA Technical Implementation Procedure (TIP) rev 5, paragraph 3.2.8.2 EASA Acceptance of FAA Alteration Data:
“Except for alterations on critical components, FAA-approved or accepted alterations per 14 CFR Part 43 installed on a used aircraft exported from the U.S., regardless of the State of Design of the aircraft, are considered approved by EASA at the time of import to the European Union. EASA shall accept such FAA alteration data when substantiated via an appropriately executed FAA Form 8110-3, FAA Form 8100-9, FAA Form 337 or logbook entry.
Alterations on critical components must be EASA-approved via STC, in accordance with TIP paragraph 2.2 (Design Approval Procedures for Supplemental Type Certificates (STCs)).
An FAA STC whose installation is documented on a Form 337 must be approved by EASA in accordance with TIP paragraph 2.2.”

From the aforementioned TIP:

2.2 Design Approval Procedures for Supplemental Type Certificates (STCs).
2.2.1 Scope of STC Application Acceptance.
2.2.1.2 EASA may accept applications
  for STCs for:
(a) All STCs (Basic and Non-Basic) when the original STC application is made to the FAA:
(1) On products for which EASA acts on behalf of the State of Design,
(2) On U.S. State of Design products, and
(3) On third country aircraft which have been type certificated by both EASA and the FAA.

So you should be able to apply per point 2.2.1.2.a.3, assuming of course, that the aircraft is certified by EASA and not operated within Europe as an experimental with a Permit-to-Fly.
In light of the above, and considering that a modification of the wing to carry an external load is not likely to be classed as non-critical, you should probably contact both EASA and the Design Organization for the type.
Alternatively, you could look into moving the aircraft into the experimental category
In this case you will need a Permit-to-fly, more info here:

The European Aviation Safety Agency (EASA) is responsible for the approval of flight conditions. Such an approval is the basis on which a Permit to Fly (PtF) can be issued by the Competent Authority of the State of Registry, or of the State prescribing the identification marks of an aircraft.
A PtF is generally issued when a certificate of airworthiness is temporarily invalid, or when a certificate of airworthiness cannot be granted, but the aircraft is nevertheless capable of performing a safe flight.
Please use EASA Form FO.CERT.00037 (with EASA Form 18B in the annex) to apply for approval of flight conditions at EASA. With the approved flight conditions (EASA Form 18B) you can apply for a Permit to Fly at the local national aviation authority the aircraft is registered.

Your answer tackles the upcoming certification problems nicely however it doesn't discuss the actual engineering part. Maybe you can elaborate a bit on this as well?

@Chris I'll add to that a bit later, but it depends significantly on the wing structure, and I am not familiar with this type. It is not a straightforward process either.

maybe the construction manual is helpful: https://airplanefactory.co.za/download/110/sling/4771/03-sling-2-wing-construction-manual-1-9.pdf (8,1 MB) Maybe you have some further reading for me where I can broaden my knowledge.

@Chris thanks, that looks like I expected it to, but I did not want to assume. How large would your external stores be? The best option would probably be to attach them to a rib. In my experience we used the spar, but only because it was a composite airframe and the stores were too heavy for the sandwich ribs.


text:
What is this plane shown on the 'Blended wing body' Wikipedia page?

(wikimedia.org via wikipedia.org)
What is the second plane from left, between the 757 and the B-2?

Its a Rockwell B-1 Lancer a heavy bomber used by the USAF.

(source)

Thanks, Dave! Wikipedia refers to the B-1 as a "variable-sweep wing" aircraft, which would mean that is definitely not a "blended wing body" aircraft, right?

@CCC being a variable-sweep wing does not exclude you from being a blended wing aircraft. I'd say the B-1 has " no clear dividing line between the wings and the main body of the craft.

Do you know what model specifically by any chance?

@dalearn there is only one operational model of the B-1, the B-1B. The B-1A existed only as a few prototypes, which were painted in reflective white with a bright blue flash.

@CCC: Look for a picture with the wings swept back in high-speed cruise configuration. You can definitely see much less of a clear delineation between wings and body, than in the wings swept-forward low-speed configuration.

It is a B-1 bomber, also affectionately referred to as the "Bone".


text:
Why can't pilots manually fly a low visibility approach instead of using auto land?
Pilots have instruments that help them land. But in low visibility they are required to use auto land. Why can't they rely on their instruments at those times?

Welcome to aviation.SE! I think you're asking about airliners (I may be wrong!) but this question might be helpful.

"... are required to use autoland..." is not a correct statement (or assumption).

@RalphJ: It is in very low visibility.

@Sean With a HUD, Cat IIIA can be hand-flown down to 600 RVR.  That's as low as most pilots are likely to see for years at a time.  At 500 RVR or less, then a IIIB autoland is needed, but there's nothing to indicate that the OP is only asking about 500 RVR and less; it's simply a misunderstanding on his part of what's required.

Pilots are required to operate by two separate sets of regulations, protocols, and procedures when flying an aircraft. They are Visual Flight Rules (VFR) and Instrument Flight Rules (IFR). The rules are dependent upon what type of airspace you are flying in as well as cloud ceilings and visibilities outside the aircraft. Most commercial flights, including virtually all scheduled airline services are conducted under IFR.
Landings conducted under VFR must be done by flight under visual references and are subject to specific limitations on cloud ceiling and visibility minimums for the specific airspace surrounding an airport. If the local weather drops below these minimums, you cannot takeoff or land under VFR and the airport can only accommodate IFR traffic in this weather.
IFR operations require pilots to fly specific procedures during departure and approach to an airport. These procedures themselves set weather limitations on the flight depending on aircraft and airport equipment, NavAid availability and GPS reception and the specific regulations in which the flight operation is being conducted under eg. Part 91, 121, 135, etc. If the weather does not meet these minimum requirements, the flight is not permitted under IFR either, which is why airline flights get cancelled in bad weather such as snowstorms, etc.
IFR Instrument Approaches into airports are broadly divided into 2 categories: Non-precision approaches, which provide lateral guidance to either the runway threshold for a straight in approach or to the airport itself for a visual circling approach and landing.  Precision approaches provide the pilot with both lateral guidance to the runway center line and a glide path to the runway touchdown zone. Both types of approaches have minimum ceiling and visibility requirements along with specific minimum altitudes and decision points based on your aircrafts’s approach speed. If you do not have the runway environment in sight when flying these approaches at these points and altitudes you cannot continue the approach to landing under visual conditions and must fly the missed approach procedures specific to this instrument approach.
The most common type of Precision Instrument Approach is the Instrument Landing System or ILS which uses terrestrial radio signals to guide the pilot along an approach path and identify specific points in the approach. ILS approaches fall under 3 different categories, or CATs.  CAT I approaches are standard ILS approaches and can be flown by most IFR Certified aircraft. CATs II and III approaches require specific additional flight crew training, and aircraft equipment.
CAT III approaches are the most precise ILS approaches and have 3 three additional subcategories: IIIa is the most precise approach that still allows the pilot to hand fly an aircraft equipped with an approved HUD. IIIb, and IIIc require the use of a coupled autopilot and allow for even lower weather minimums. CAT IIIc approaches are “zero-zero” meaning they can be flown with ceilings of 0 ft AGL and visibilities less that 1/16 of a mile, though they do require the visibility be great enough to adequately allow the crew to taxi the airplane off the runway environment to parking. Again these are limited to specifically trained flight crews, specifically equipped aircraft and specific airport infrastructure.
While CAT IIIb and IIIc ILS approaches do require a coupled autopilot to perform them, all other Non-precision and Precision Instrument approaches can be flown by hand - and all aircrews should be able to do this in the event of an autopilot failure.

a most thorough response, and quite informative. -NN

CAT II approaches do not legally require an autopilot or auto land capability, but most company procedures or SOP’s will require it.

Because the minimums are so low, you simply don’t have the reaction time as a human to make corrections that close to the ground without greater visibility.

@CarloFelicione: So could a IIIB approach be hand-flown in a sufficiently-slowly-flying aircraft (like if someone pimped out an An-2 with ILS receivers)?

Negative.  The RVR as well as the ceilings on an approach like that do not facilitate the needed visibility for a pilot to properly judge the approach and roundout phases of the landing to safely make the landing.  Add into this gusty winds, precipitation, etc., this creates a dangerous situation for a pilot to attempt such an approach by hand.  You would have to be crazy/suicidal to try it.  And no company SOP is going to clear you to do so with 100+ lives on board.


text:
Wind correction on downwind during circling
A timing must be started when flying abeam the threshold on a circling approach. The FCTM of the B777/787 mentions 35 seconds and the SOPs of the Embraer 190 30 seconds. Do they need to be corrected for head/tailwind? If yes, how are they corrected?

Yes, they need to be corrected, mainly for two reasons:
1) Legally, the horizontal criteria for circling is the distance from the threshold of each usable runway (search for TERPS circling criteria if you are interested in US rules, or PANS-OPS circling criteria for the rest of the world). In other words: you need to stay within a given distance of the runway. If you have a very strong tailwind, without correcting for it, you might leave the circling domain.
2) In order to facilitate the base/final. If you have a very strong headwind (which is indeed not very likely, as it means you will land in a very strong tailwind), you will drift towards the runway during your entire base/final-turn. This means you will roll out on the final course a lot closer to the runway than you would in zero wind. This could be a problem, since your stable approach criteria usually requires you to be "wings level" at some altitude (typically 300 ft for circling).
Now, for the how, this will depend on aircraft and operator. One example is however to add/subtract half the wind component in knots from your timing in seconds. Example: Zero-wind outbound: 30 s, Tailwind component: 20 kt. Wind-corrected outbound: 30 - 0.5*20 = 20 s.
(In addition, outbound timing is usually also determined by circling height, since the higher you are, the longer you will need for your descent. A typical SOP here is to take the circling height in hundreds of feet, and multiply it by 3, to get your zero wind outbound timing. Example: Circling height: 1000 ft. 1000/100 * 3 = 30 s.)


text:
What is the Runway Design Code (RDC) for San Francisco airport (KSFO)?
I need the Runway Design Code (RDC) for the SFO airport. Can anyone provide a link for this and possibly other airports? I have checked the SFO Master Plan/Development Plan and found nothing.

Why do you need it? I suspect that you're looking for some fact that you believe will be in it. As a general rule, then, ask about that fact rather than asking for where to find a specified resource, whether or not that resource might provide the fact sought. That way the question (and its answer(s)) will remain useful even after the specific resource sought becomes unavailable, should that happen.

Why can't I ever get a straight answer on this sight?

@MichaelKjörling I'm not sure what you meant by "in it", but the RDC isn't a code in the sense of "a collection of rules and guidelines"; it's a single value per runway that tells you what type of aircraft and operations it was designed to handle. This question is like asking for the runway length, surface or some other specific characteristic. At least, that's my understanding after quickly searching; I'd never heard of the RDC before.

https://www.faa.gov/documentLibrary/media/Advisory_Circular/draft_150_5300_13a.pdf#page271

@P-dub the XY problem has been the cause of a lot of wasted time on SE sites, whose communities are kept alive by volunteers. Please don't be disrespectful when community members ask for clarifications about your question.

D-VI. No link. A380 requires this and operates there, so that is minimum.
E is military, VI is a high as it goes.

Looks like some folks use ARC (which should be for the entire airport, not just for one runway) when they really mean RDC.  This is a 2011 doc for SFO (which confirms the D-VI code).  Codes are on page 7.
San Francisco International Airport
Runway Safety Area Program


text:
Why does the B777-200 freighter not use the letters I, N, O and Q for deck positions?
The B777-200 Freighter has positions on the main deck to describe how the cargo will be loaded in a left to right sequence. They are identified as A, B, C, D, E, F, G, H, J, K, L, M, P and R.
What is the reason that the letters I, N, O, and Q are omitted?

Those letters are commonly unused in aviation in markings, registrations etc. They might be easily confused with similar letters (I with J, N with M) and are therefore left out.

Also O&Q are often mistaken and with some people’s handwriting even C. Also I can be mistaken for number 1 or lowercase L

N turns into Z sideways. O looks like zero. I looks like one. Q and O are hard to distinguish.

I see all US civialian aicraft with N marking.


text:
How is Kool-Aid used as a visual cue to create contrast for an off-airport landing?
In part 7-5-13 of the AIM, there is quite peculiar guidance given:

g.  Off-Airport Landings.

In the event of an off-airport landing, pilots have used a number of different visual cues to gain reference.  Use  whatever  you  must  to  create  the contrast you need. Natural references seem to work best (trees, rocks, snow ribs, etc.)
(a) Over flight.
(b) Use of markers.
(c) Weighted flags.
(d) Smoke bombs.
(e) Any colored rags.
(f) Dye markers.
(g) Kool-aid.
(h) Trees or tree branches.

How exactly is Kool-Aid going to assist in an off-airport landing?

But in what way is Kool-Aid worth noting in this context?

@JonathanBell Because it is, in the FAA's opinion, a good option. Low cost, readily available, biodegradable and non-toxic.

I will now be packing Kool-Aid packets in a pocket of my flight bag, "just in case." And it'll be a great conversation starter. Wow, this blows my mind. What a gem!

Kool-Aid is usually brightly colored due to added dye. It comes in powdered form, and you would normally add water to make a solution.
If you have some in your aircraft in a suitable container (perhaps a paper bag), you can drop it on the ground during an overflight of an off-airport landing location. Hopefully the bag will burst on impact. When you return for an actual landing, the brightly colored powder can be a useful visual reference. This is especially important for landing with undistinguished surface cover such as snow.
Doing this successfully will take some practice, because you have to drop the right amount, in such a way that it breaks and spreads on the ground, at a suitable location, from some height that maintains your margins of safety. And if you're doing an off-airport landing in the first place, you probably have some other emergency going on at the same time.

Learning how to accurately bomb Kool-Aid powder for the first time while dealing with an aircraft emergency seems like a strange plan to me, but that seems to be what the AIM is saying. Once down, though, red or orange Kool-Aid powder will be an excellent way to mark snow, as a very distinctive indicator of human presence.

Where do you see an aircraft emergency?  Are you suggesting that an off-airport landing is an emergency?   (https://www.youtube.com/results?search_query=off+airport+landing)

@abelenky: No, I'm not suggesting that an off-airport landing is always an emergency. It depends on your plan. When I flew gliders, an off-airport landing almost always meant something was going wrong (and you don't even get a chance for a proper overflight in a glider). On the other hand, there are certainly situations where an off-airport landing is exactly part of the plan and not an emergency.

Re off airport landings & emergencies, not necessarily so.  Some of my favorite places involve landing on dry lake beds.  And of course there's Alaska...


text:
Is it possible to remove an A320's main gear using one main jack and one nose jack?
I have only one set of jacks (nose-main LH and RH) and I need to swap the main landing gear from one aircraft to another. I don't have a dummy landing gear. Is this possible?

Please do not shout in the title or in the post. It will get you attention but not the type you're hoping for.

This is the type of question that you should be asking to Airbus directly.  I'm sure they have some product support people that can help you solve the problem.

If the maintenance manual says to use two main gear jacks, then use two main gear jacks. Using anything other than that makes you liable for any injuries or damage to equipment. Don’t let your lead push you around. Tell him to pound salt or get you another jack. Guys who cave to pressure like this make it tough for every other mechanic in the world who try to do things right. All we hear the rest of our careers are from guys who did things wrong and say, “Well, at ‘X’ airlines we didn’t have problems doing it this way.”
Furthermore, by not doing it right this time, you set the precedent to do everything else wrong every time. It’s like blackmail. “Boss, I don’t feel comfortable changing the engine with a 2x4 and a fishing pole.” Their response? “Remember when you did the lopsided gear change? You didn’t have any problems then, did you?”
Do it right or go find a job where shoddy workmanship won’t get people killed.

His title is misleading.  He means one set of jacks.  His problem is he needs to have two aircraft jacked at the same time.  Any solution would be a lot more hassle than simply renting a second set of jacks.  My guess is that this is a college student fishing for an answer after a beer bet.

Negative. This sort of thing happens all the time in “the real world.” Contract maintenance vendors are notorious for having only a partial amount of equipment or the absolute bare minimum. This is probably some lone mechanic or small group of mechanics in some remote contract maintenance station who are trying to skirt the books. It’s bad business all around because “getting the job done,” albeit incorrectly, is what keeps those 3rd party vendors open, makes it cheap for airlines, and costs real A&P jobs. IMO, it jeopardizes air safety. So the only real answer is to follow the book.


text:
What is the meaning of "static pressure"?
I don't really know what static pressure is. Does the ASI (Airspeed Indicator) use cockpit pressure as static pressure, to find the dynamic or differential pressure?
I just found this statement :

if the instrument static pressure line becomes disconnected inside a
       pressurized cabin during cruising flight the altimeter and airspeed
       indicator will both read low.

Could anyone help me understand static pressure and this statement?

See here for clues: https://aviation.stackexchange.com/questions/12141/why-does-the-static-pressure-inside-the-cockpit-vary-from-outside-static-pressur

There is a static pressure port, often on the side of the aircraft, that senses the air pressure at the altitude the aircraft is flying and unaffected by the aircraft's passage through the air.
The pitot tube, facing into the relative wind caused by the aircraft's passage through the air, measures the ram air pressure, which is higher the faster you go.
The indicated airspeed is the difference between the ram air pressure and the static pressure, subject to some adjustment due to sensor positioning.
The altimeter operates off the static air pressure.
So, if the static line is somehow opened to the inside of a pressurized cabin, the system will read that higher pressure and believe the altitude is what it is inside the pressurized cabin, which will be significantly less than the actual altitude.
And the difference between the ram air pressure and the false higher static pressure (the pressure inside the cabin) will be much less and the system will read this reduced different as a much lower speed.
This is a somewhat simplified answer.

A minor note: on most light aircraft the static inlet is a small metal disk about the size of a Canadian $2 coin, with a hole in the center. They are quite distinctive and you can see them in most photos.

For any fluid that is not compressible, (as air flowing at subsonic speed is) the total pressure must remain constant. This is the essence of Bernouli's principle, which is based on conservation of energy. So since the total pressure must remain constant, when air is flowing at some velocity (less than subsonic) relative to the measuring instrument, the pressure measured parallel to the flow (the dynamic, or ram, pressure) increases as the velocity increases, so the pressure measured perpendicular to or across the flow must decrease in order that the total remain the same. This pressure, measured perpendicular or across the flow, is referred to as the static pressure.
In an aircraft we measure these two pressures by simply orienting two measurement sensors appropriately, one (the pitot tube) parallel to the flow, and which displays on the airspeed indicator, and the other (a static port), with the opening perpendicular to the flow, which displays on the altimeter.
Because the airspeed indicator measures the dynamic pressure pressing on the pitot tube, even at zero airspeed there would be some pressure there, in order to make the displayed value measure airspeed, you must subtract the zero airspeed pressure, so the membrane inside the airspeed indicator has the dynamic (ram) air pressure on one side,, and the static pressure from the static port on the other side, and therefore moves only according to the difference between them, i.e., according to that amount of Ram air pressure which is greater than the static pressure, i.e, the pressure in the pitot tube due to motion through the air.


text:
Could airliners have cameras to let the pilots see the engines and wings?
Why can't jet airliners have a camera installed on the fuselage and a monitor in the cockpit so that pilots can see engines and wings which are normally behind them and hidden from view? Something like the system they have in cars today?
This might help in an emergency engine fire or wing damage. I don't believe that any jet transport today has cameras to monitor the wings and engines (I see where they do have other cameras) and this was the cause of a recent accident where an engine was on fire after landing and the pilots were unaware of it until the fire was out of control and the pilots were almost killed.

Also Why don't airliners have any mirrors or cameras?, but they're more intended for ground maneuvering than assessing damage.

Because cost is non-zero while benefit is small. Similarly why cars doesn't have fire extinguishers as standard equipment ?

I don't think this is an exact dupe: the other questions are focused on taxiing and visibility around the aircraft, whereas this one is about visibility of the aircraft itself. I suppose one camera could address both, but I'm not sure that's the case.

"a recent accident where an engine was on fire after landing and the pilots were unaware of it until the fire was out of control and the pilots were almost killed." Which one was that? Flight number, aircraft tail number, anything on which to base a search?

China Airlines Flight 120. Smithsonian Air Disasters "Deadly Detail". Don't know tail number.

https://www.smithsonianchannel.com/videos/raw-footage-of-the-china-airlines-flight-120-explosion/59702


text:
What is the difference between an engine "shut down", "cut-off" and "cut down"?
Explain please for non-native speakers the difference between these engine (jet or piston) terms:

shut down
cut-off
cut down

I'm studying at a civil aviation university to become a pilot and a teacher told me "shut down" is used when you switch the engine off, "cut-off" is used when the engine electrical supply fails, and "cut down" is when you reduce throttle setting. But I'm not sure it's correct.

"Cut down" typically means "lower the speed", usually via a throttle.

I think we need more context. What University? What course of study? What is the language being spoken? (is there a translation problem?)

@MikeSowsun okay, check update.

@MikeSowsun I don't have text in which i found these phrases.

also consider the case of "engine fall off"

This answer may be difficult to answer as these terms can have different meanings which can vary according to specific aircraft types. I have never heard “cut down” used in aviation. On the Boeing 777 (and many other Boeing aircraft) the Fuel Control Lever has 2 positions: “Run” and “Cutoff”.  “Cutoff” is the normal way to “Shut Down” or turn off the engine.

To be specific:
Shutdown: To take a step or series a steps to stop the operation of a machine and put it into its normal inoperative state. A shut-down procedure may include cutting off fuel, closing valves, and turning off pumps, or may just be flipping a switch to OFF.
Cut-off: To interrupt (or a noun describing something that interrupts) the supply of something to a machine; fuel, water, electricity.  Generally refers to closing of a valve or opening an electrical contactor or switch.  On a piston engine, you have a mixture setting called "idle cut-off" that blocks flow of fuel at the carburetor. You might see a switch that opens a contactor to an electrical bus, for use in emergencies, labelled "Bus XXXX Cutoff".
Cut-down: I've been working in aviation in N America since 1975 and have never heard of this term as relating to operation of an engine (maybe in UK?).  Normally if I see the word cut-down it's an adjective that describes something that has been physically altered to make it shorter or smaller.  Like a cut-down vertical fin, or a cut-down antenna, or cut-down propeller blades.  I'd be surprised if anybody on here has ever heard of the phrase "cut down power" as an instruction to reduce power, or thrust.  You just say "reduce".
You DO sometimes hear the word "Cut" by itself as an instruction to go to idle or to remove power completely on an engine.  A skydiving pilot may get an instruction to "Cut" when it's time for jumpers to exit.  Some day when you are on a jet type course, one of the simulator sessions will include "V1 Cuts", where one engine is failed just as you are passing V1 (whereupon hilarity ensues the first time you do it).  So in those cases, power is cut, but not "cut-down".

I‘ve never heard „cut down“ in the UK either (other than in gardening and landscaping). Definitely not anywhere close to aircraft engine operation.

Now it's clear, thx.

Is there a special phrase for a situation when engine stops working by itself in flight(not due to some malfunction, so it is possible to start it up again in flight)?

In-Flight Shutdown.  In a jet say, there is often a dedicated procedure in the Quick Reference Handbook for shutting down and "securing" an engine, which could be discretionary or following a failure, and may be one procedure or separate procedures for each case.

For reducing power there is also a more specific alternative ‘retard’.

@Nikita, there is no phrase that would distinguish transient and permanent failures, because when the engine stops on its own—which would be called ‘uncomanded shutdown’ or ‘in-flight shutdown’, or specifically of turbines ‘flame out’—you don't know whether the failure is transient (the engine can be restarted) or permanent. It is a failure by definition, because the engine is supposed to continue running until the pilot shuts it down.

As an informal term an engine can also ‘cut out’ in flight, which would be an unintended shut down, or even a transient loss of power.

The FAA Airman's Information Manual essentially describes "Cut" as the same as "Shut Down". I have heard some refer to "Shut Down" as what is done during normal operations and according to normal operating procedures. While a "Cut" is when a problem exists which would necessitate such an immediate shut down that normal checklist protocols, such as a cool-down period, would be obviated.